Japanese Laid-Open Patent Publication No. 2012-181389 discloses a so-called electrodeposition element. The electrodeposition element mainly includes a pair of electrodes facing each other and an electrolyte layer held between the pair of electrodes and containing an electrodeposition material including silver.
In a steady state (when no voltage is applied), the electrolyte layer is substantially transparent and the electrodeposition element is in a transparent state. When a voltage is applied across the pair of electrodes, due to oxidation-reduction reaction, the electrodeposition material (silver) in the electrolyte layer is deposited and accumulated on one of the electrodes. This causes the electrodeposition element to be in a mirror (highly optically reflective) state.
Japanese Laid-open Patent Publication No. 2008-120162 discloses a vehicle lighting device for adjusting a light emitting direction or light illumination area by mechanically controlling an optical member. Japanese Laid-open Patent Publication No. 2005-183327 discloses a vehicle lighting device that uses a liquid crystal element.